Arc chute assembly and method of manufacturing same

ABSTRACT

An arc chute assembly includes a housing having a first wall, a second wall, and a pair of side walls coupled to the first wall. The walls configured to form an arc area. The housing further having a divider wall coupled to the first wall between the side walls. The divider wall configured to form a first sub-arc area, a second sub-arc area, and an arc plate area. The first sub-arc area and the second sub-arc area are configured to be in flow communication with the arc plate area. The arc chute assembly further comprises a support coupled to the first wall and the side walls, and an arc plate coupled to the support. The arc plate having a body extending between the side walls and over the divider wall.

BACKGROUND OF THE INVENTION

The embodiments described herein relate generally to an arc chuteassembly for a circuit breaker, and more particularly, to methods andsystems used to distribute gas pressure formed within a circuit breaker.

The capability of circuit breakers for current-interruption can bedependent, in part, upon the ability to extinguish the arc that isgenerated when the breaker contacts open. Even though the contactsseparate, current can continue to flow through the ionized gases formedby vaporization of the contacts and surrounding materials. Circuitbreakers require expedient and efficient cooling of the arc tofacilitate effective current interruption. Circuit breakers includesub-poles that are located in arc chutes. The arc chutes are configuredto extinguish the arc that is produced when the breaker is tripped andthe contacts of the breaker are rapidly opened. Typically, each arcchute is associated with a single phase, for example, one phase of a3-phase power distribution system.

Conventional arc chutes include a series of metallic plates that areconfigured in a spaced apart relationship and held in place bydielectric side panels. When the contacts of the breaker are opened, theresulting arc is driven to the metallic plates of the arc chute wherethe arc is then extinguished by the plates. The metallic plates increasethe arc voltage in the circuit breaker to produce a current-limitingeffect thereby providing downstream protection.

Each sub-pole for the current path of the circuit breaker includes anarc chute. The sub-poles are electrically connected in parallel andseparated inside the circuit breaker by a divider wall. Due to componentvariations, one sub-pole may experience a higher pressure than the othersub-pole when the breaker is tripped. While increasing the volume of gasgenerated during current-interruption and enhancing current flow aids inextinguishing the arc, the increased volume of gas increases pressurewithin the sub-poles, and therefore, on the arc chute and the circuitbreaker housing. In some cases, the sub-pole that is exposed to thehigher pressure may experience damage to the housing walls and the arcchute which may limit the current-interruption capability of the circuitbreaker.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, an arc chute assembly is provided. The arc chute assemblycomprises a housing having a first wall, a second wall, and a pair ofside walls coupled to the first wall. The walls configured to form anarc area. The housing further having a divider wall coupled to the firstwall between the side walls. The divider wall configured to form a firstsub-arc area, a second sub-arc area, and an arc plate area. The firstsub-arc area and the second sub-arc area are configured to be in flowcommunication with the arc plate area. The arc chute assembly furthercomprises a support coupled to the first wall and the side walls, and anarc plate coupled to the support. The arc plate having a body extendingbetween the side walls and over the divider wall.

In another aspect, a power distribution system is provided. The powerdistribution system comprises a housing having a first wall, a secondwall and a pair of side walls coupled to the first wall. The first walland the side walls are configured to form an arc area. The housingfurther having a divider wall coupled to the first wall between the sidewalls. The divider wall configured to form a first sub-arc area, asecond sub-arc area, and an arc plate area. The first sub-arc area andthe second sub-arc area are configured to be in flow communication withthe arc plate area. The power distribution system further comprises asupport coupled to the first wall and the side walls, and an arc platecoupled to the support. The arc plate having a body extending betweenthe side walls and over the divider wall. The power distribution systemalso comprises a circuit breaker coupled to the housing and having afirst sub-pole coupled within the first sub-arc area and a secondsub-pole coupled within the second sub-arc area.

In a further aspect, a method of manufacturing an arc chute assembly isprovided. The method comprises forming a housing having a first wall, asecond wall, and a pair of side walls coupled to the first wall. Thewalls are configured to form an arc area. The method also comprisespositioning a divider wall between the side walls. The divider wallconfigured to form a first sub-arc area, a second sub-arc area, and anarc plate area within the housing. The method further comprises couplingan arc plate to the housing. The arc plate having a body extendingbetween the side walls and over the divider wall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic block diagram of a circuit breaker.

FIG. 2 illustrates a top perspective view of a housing assembly usedwith the circuit breaker shown in FIG. 1.

FIG. 3 illustrates a front perspective view of a portion of the housingused with the circuit breaker shown in FIG. 1.

FIG. 4 illustrates a front view of an exemplary arc plate.

FIG. 5 illustrates a front perspective view of a support coupled to thearc plate shown in FIG. 4.

FIG. 6 is a front perspective view of the support and arc plate coupledto the housing shown in FIG. 3.

FIG. 7 illustrates a front perspective view of a plurality of circuitbreakers and arc chute assemblies.

FIG. 8 is an exemplary flowchart illustrating a method of manufacturingan arc chute assembly.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a schematic block diagram of a power distributionsystem 10 that includes a power source 12, a circuit breaker 14, and apower load 16. Power source 12 includes a line, such as, but not limitedto, an incoming power line. Power load 16 includes an output, such as,but not limited to, an electrical device or a circuit. Circuit breaker14 includes a contact assembly 18 and an arc chute assembly 20. In oneembodiment, circuit breaker 14 includes a first sub-pole 22 and a secondsub-pole 24. Each sub-pole 22 and 24 has movable contacts 26. Arc chuteassembly 20 includes a housing 28, an arc plate 30, and a support 32.Arc chute assembly 20 is configured to facilitate distributing gaspressure formed when breaker contacts 26 open under an over-current loadcondition. Arc chute assembly 20 is also configured to facilitatequenching an electric arc formed when breaker contacts 26 open duringthe over-current load condition.

FIG. 2 illustrates a top perspective view of a housing assembly 33 usedwith the circuit breaker shown in FIG. 1. Housing assembly 33 includesthree arc chambers, or arc areas, 34 formed by first housing 28 and asecond housing 36. First housing 28 includes a first wall 38 and a pairof side walls 40, 42 coupled thereto and extending therefrom. Secondhousing 36 includes a second wall 44 and a pair of side walls 46, 48extending therefrom. First housing 28 is connected to second housing 36such that first housing side walls 40, 42 contact second housing sidewalls 46, 48, respectively.

FIG. 3 illustrates a front prospective view of first housing 28 usedwith power distribution system 10 (shown in FIG. 1). First housing 28 isconfigured to withstand gas pressures generated when circuit breakercontacts 26 (shown in FIG. 1) open during an over-current loadcondition. First housing 28 includes a divider wall 50. First wall 38includes a top 52, a bottom 54, an inner side 56, and an outer side 58.Side wall 40 couples to inner side 56 and extends outward from innerside 56. Side wall 40 includes a top 60, a bottom 62, and a height H1extending between top 60 and bottom 62. Side wall 42 couples to innerside 56 and extends outward from inner side 56. Side wall 42 includes atop 64, a bottom 66, and a height H2 extending between top 64 and bottom66. Divider wall 50 couples to inner side 56 and extends outward frominner side 56. Divider wall 50 includes a top 68, a bottom 70, and aheight H3 extending between top 68 and bottom 70. In one embodiment,height H3 of divider wall 50 is less than at least one of height H1 andheight H2.

First wall 38 and side walls 40, 42 form at least a portion of arc area34. Arc area 34 has a width W extending from side wall 40 to side wall42. Divider wall 50 is positioned between side walls 40, 42 such thatdivider wall 50 and side wall 40 form a first sub-arc area 72 anddivider wall 50 and side wall 42 form a second sub-arc area 74. Inaddition, an arc plate area 76 is positioned over divider wall 50. Firstsub-arc area 72 and second sub-arc area 74 open into arc plate area 76and are in flow communication with arc plate area 76. First sub-arc area72 has a width W1. In one embodiment, width W1 is less than width W ofarc area 34. Second sub-arc area 74 has a width W2. In an embodiment,width W2 is less than width W of arc area 34. In the exemplaryembodiment, width W1 is substantially the same as width W2.

FIG. 4 illustrates a front view of arc plate 30. Arc plate 30 couples tosupport 32 (shown in FIG. 1) to facilitate quenching arc energy. Arcplate 30 includes a first end 78, a second end 80, and a body 82extending between first end 78 and second end 80. In one embodiment,body 82 is formed from an electrically conductive and/or magneticmaterial such as, for example, steel to facilitate attracting arcenergy.

Arc plate 30 includes a first recess 84, a second recess 86, and a thirdrecess 88 such that first recess 84, second recess 86, and third recess88 extend into body 82. First recess 84 and second recess 86 areconfigured to permit movement of contacts 26 (shown in FIG. 1). Thirdrecess 88 is configured to facilitate positioning arc plate 30 withinhousing 28 (shown in FIG. 3). In one embodiment, third recess 88 ispositioned between first recess 84 and second recess 86.

First recess 84 is defined by edges 90 and second recess 86 is definedby edges 92. In one embodiment, edges 90 are angled toward each otherand edges 92 are angled toward each other. In the exemplary embodiment,first recess 84 and second recess 86 are substantially “V”-shaped. Inalternative embodiments, first recess 84 and second recess 86 includeother shapes, such as, but not limited to, rounded shapes to permitmovement of contacts 26.

Third recess 88 is defined by an edge 94. In the exemplary embodiment,third recess 88 is substantially “U”-shaped and is configured to permitpositioning of arc plate 30 over divider wall 50 such that divider wall50 extends at least partially within third recess 88. Third recess 88can include other shapes such as, but not limited to, angled shapes thatpermit positioning arc plate 30 within housing 28. In one embodiment,third recess 88 is complimentary to a shape of top 68 of divider wall50.

FIG. 5 illustrates a first perspective view of support 32 coupled to aplurality of arc plates 30. In one embodiment, support 32 is coated withgas evolving materials such as, but not limited to, cellulous filledmelamine formaldehyde, glass polyester filled with alumina trihydrate(ATH) or by providing inserts made of such materials to facilitatedistributing an increased volume of gas generated during currentinterruption.

Support 32 is configured to facilitate coupling arc plates 30 to firsthousing 28 (shown in FIG. 3). Support 32 includes a first top section96, a second top section 98, and a vent section 100 coupled to first topsection 96 and second top section 98. First top section 96 includes afirst side wall 102 configured to hold at least one arc plate 30. Secondtop section 98 includes a second side wall 104 configured to hold atleast one arc plate 30. In one embodiment, each side wall 102 and 104includes a fastener 106 configured to couple to arc plate 30. Fastener106 is sized and shaped such that arc plate 30 can be removably coupledthereto.

FIG. 6 is a front perspective view of a plurality of arc plates 30 andsupport 32 coupled to first housing 28. For illustrative purposes, FIG.6 illustrates three arc chute assemblies 20. In alternative embodiments,any number of arc chute assemblies 20 can be used to facilitateoperation of circuit breaker 14 (shown in FIG. 1). In one embodiment,first top section 96 is coupled to first wall top 52 and to side walltop 60 and second top section 98 is coupled to first wall top 52 and toside wall top 64. In the exemplary embodiment, vent section 100 ispositioned between first top section 96 and second top section 98.

In one embodiment, each arc plate 30 is coupled to support 32 and ispositioned within arc area 34. In the exemplary embodiment, each arcplate first end 78 is coupled to first top section 96 in a positionadjacent housing side wall 40. In addition, each arc plate second end 80is coupled to second top section 98 in a position adjacent housing sidewall 42. Each arc plate 30 extends within and across arc plate area 76in a position over first sub-arc area 72 and second sub-arc area 74.First recess 84 is positioned over first sub-arc area 72 and secondrecess 86 is positioned over second sub-arc area 74. Further, asillustrated, each third recess 88 is positioned over divider wall 50.

Arc plates 30 are positioned and interconnected parallel to one anotherwithin support 32. Arc plates 30 are laterally offset relative to oneanother in the same direction so that cavities formed by individualrecesses 84 and 86 follow the radii of each moveable contact 26. Asfurther illustrated in FIG. 6, arc chute assembly 20 further includes atleast one cover plate 108 coupled to support 32. Cover plate 108 isconfigured to facilitate aligning arc plates 30 within support 32. Forillustrative purposes, two exemplary arc chute assemblies 20 are shownthat include cover plate 108 and one exemplary arc chute assembly 20 isshown with cover plate 108 removed.

FIG. 7 illustrates a front perspective view of three arc chuteassemblies 20 and contact assemblies 18. In alternative embodiments,more or less than three arc chute assemblies 20 are used to facilitateoperation of circuit breaker 14 (shown in FIG. 1). Each arc chuteassembly is associated with one phase of a 3-phase power distributionsystem. More specifically, first sub-pole 22 and second sub-pole 24 areassociated with a single phase of power received from power source 12(shown in FIG. 1). First sub-pole 22 and second sub-pole 24 are coupledto housing 28. In the exemplary embodiment, first sub-pole 22 is coupledwithin first sub-arc area 72 adjacent side wall 40 and second sub-pole24 is coupled within second sub-arc area 74 adjacent side wall 42. Firstsub-pole 22 and second sub-pole 24 are arranged on opposite sides ofdivider wall 50 within respective sub-pole arc areas 72 and 74. Sidewalls 40, 42 and divider wall 50 mechanically associate sub-poles 22 and24 with each other for structural support to facilitate sub-poles 22 and24 withstanding stresses when circuit breaker operates or “trips” toopen contacts 26 during an over-current load condition. Contacts 26 offirst sub-pole 22 are positioned partially within first recess 84 andcontacts 26 of second sub-pole 24 are positioned within second recess86. Cavities formed by respective individual recesses 84 and 86 followthe radii of each moveable contact 26 during the over-current loadcondition.

During an exemplary mode of operation, current flows from power source12 (shown in FIG. 1) through circuit breaker 14 to power load 16 (shownin FIG. 1). When an over-current load condition occurs, circuit breaker14 trips to facilitate current interruption between power source 12 andpower load 16. The tripping of circuit breaker 14 causes contacts 26 offirst sub-pole 22 to rapidly open and pivot through cavities formed byfirst recess 84 of arc plates 30 and causes contacts 26 of secondsub-pole 24 to rapidly open and pivot through cavities formed by secondrecess 86 of arc plates 30. When contacts 26 open, an electric arc maybe generated which can allow current to continue to flow through gasesformed by the arc. The gas formation by the arc increases pressurewithin arc chute assembly 20.

Divider wall 50 is shorter than side wall 40 and side wall 42 such thatarc plate area 76 extends between side wall 40 and side wall 42 and overfirst sub-arc area 72 and second sub-arc area 74 to provide an increasedvolume within arc chute assembly 20 compared to conventional arc chutes.The height of divider wall 50 permits flow communication between firstsub-arc area 72, second sub-arc area 74 and arc plate area 76 to allowpressure equalization between first sub-arc area 72 and second sub-arcarea 74. Arc chute assembly 20 is thus configured to distribute gaspressure formed as contacts 26 of contact assembly 18 open duringover-current load conditions. Further, arc chute assembly 20 isconfigured to facilitate quenching arcs formed as contacts 26 of contactassembly 18 open during over-current load conditions. More particularly,arc chute assembly 20 directs the gas flow from one or both firstsub-arc area 72 and second sub-arc area 74 to arc plate area 76 and arcplates 30 to enhance arc cooling and more rapid termination of the arc,while simultaneously, distributing the increased gas pressure created bythe arc. Irrespective of which sub-pole 22 and 24 experiences higher arcenergy, the gas pressure applied against housings 28, 36 is dispersedand reduced due to the flow communication between first sub-arc area 72and arc plate area 76 and between second sub-arc area 74 and arc platearea 76.

Additionally, since divider wall 50 is shorter than side wall 40 andside wall 42, each arc plate 30 extends between side walls 40 and 42within arc plate area 76 and above sub-arc areas 72 and 74. Arc plates30 provide more surface area compared to conventional arc plates thatextend only above one sub-arc area since arc plates 30 extend from sidewall 40 to side wall 42 and above both sub-arc areas 72 and 74. Theinclusion of a plurality of arc plates 30 facilitates splitting the arcsinto a series of smaller arcs to quickly dissipate and extinguish thearcs. Further, cooling effects result from arc attachment to arc plates30, vaporization of arc plates 30, and discharge of gas out of ventsection 100.

FIG. 8 is an exemplary flowchart 200 illustrating a method 210 ofmanufacturing an arc chute assembly, for example arc chute assembly 20(shown in FIG. 1). Method 210 includes forming 220 a pair of housings,such as housings 28, 36 (shown in FIG. 2). The first housing has a firstwall coupled to a pair of side walls and the second housing has a secondwall coupled to a pair of side walls. The first and second walls and therespective side walls form an arc area. Method 210 further includespositioning 230 a divider wall, for example divider wall 50 (shown inFIG. 3), between the side walls to form a first sub-arc area, a secondsub-arc area, and an arc plate area within the housing. The divider wallhas a height that is less than a height of at least one of the sidewalls and the first sub-arc area and the second sub-arc area are in flowcommunication with the arc plate area.

Additionally, a plurality of arc plates, such as arc plates 30 (shown inFIG. 4), are coupled 240 to the housing and extend between the firstwall and the second wall and over the divider wall. The method includesforming a first recess, a second recess, and a third recess within thearc plate. The method also includes positioning the first recess of thearc plate over the first sub-arc area and positioning the second recessof the arc plate over the second sub-arc area such that the first recessand the second recess provide passageways for movement of contacts of acircuit breaker.

The embodiments described herein provide an arc chute assembly for acircuit breaker. The sizing, shapes and orientations of the arc chuteassembly facilitate current interruption by quenching arcs generatedduring a circuit breaker fault condition. The arc chute assembly can beused for new manufacture of power modules or to retro fit existingcircuit breakers. In one embodiment, the divider wall is shorter thanthe side walls and forms a high volume arc plate area for gasdispersion. In the exemplary embodiment, a plurality of arc platesextends across the arc plate area and above the sub-arc areas to providemore surface area for arc attachment.

A technical effect of the arc chute assembly described herein is thatthe arc plate area provides more volume for gas expansion anddispersion. A further technical effect of the arc chute assembly is thatthe first sub-arc area and the second sub arc area are in flowcommunication with the arc plate area to allow pressure equalizationbetween the first sub-arc area and the second sub-arc area. Anothertechnical effect of the arc chute assembly is that the arc plates extendacross the arc plate area to provide more surface area for arcattachment.

Exemplary embodiments of the arc chute assembly and methods ofmanufacturing are described above in detail. The arc chute assembly andmethods are not limited to the specific embodiments described herein,but rather, components of the arc chute assembly and/or steps of themethod may be utilized independently and separately from othercomponents and/or steps described herein. For example, the arc chuteassembly and methods may also be used in combination with otherelectrical systems and methods, and are not limited to practice withonly the power module as described herein.

Although specific features of various embodiments of the invention maybe shown in some drawings and not in others, this is for convenienceonly. In accordance with the principles of the invention, any feature ofa drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any layers orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

What is claimed is:
 1. An arc chute assembly comprising: a housinghaving a first wall, a second wall, and a pair of side walls coupled tosaid first wall, said walls configured to form an arc area, the housingfurther having a divider wall coupled to said first wall between saidside walls, said divider wall configured to form a first sub-arc area, asecond sub-arc area, and an arc plate area, said first sub-arc area andsaid second sub-arc area configured to be in flow communication withsaid arc plate area; a support coupled to said first wall and said sidewalls; and at least one arc plate coupled to said support, said arcplate having a body extending between said side walls and over saiddivider wall, said at least one arc plate comprising a notch configuredto receive at least a portion of said divider wall.
 2. The arc chuteassembly of claim 1, wherein said at least one arc plate is positionedover said first sub-arc area and said second sub-arc area.
 3. The arcchute assembly of claim 1, wherein said at least one arc plate includesa first recess positioned over said first sub-arc area.
 4. The arc chuteassembly of claim 1, wherein said at least one arc plate includes asecond recess positioned over said second sub-arc area.
 5. The arc chuteassembly of claim 1, wherein said divider wall has a height less than aheight of at least one of said side walls.
 6. The arc chute assembly ofclaim 1, wherein said arc plate area has a width that extends betweensaid side walls.
 7. The arc chute assembly of claim 6, wherein saidfirst sub-arc area and said second sub-arc each have a width less thanthe width of said arc plate area.
 8. The arc chute assembly of claim 1,wherein said first sub-arc area and said second sub-arc area aresubstantially the same size.
 9. The arc chute assembly of claim 1,wherein said notch comprises a substantially rectangular profile. 10.The arc chute assembly of claim 1, wherein said at least one arc platecomprises a plurality of substantially similar arc plates.
 11. A powerdistribution system comprising: a housing having a first wall, a secondwall and a pair of side walls coupled to said first wall, said firstwall and said side walls configured to form an arc area, the housingfurther having a divider wall coupled to said first wall between saidside walls, said divider wall configured to form a first sub-arc area, asecond sub-arc area, and an arc plate area, said first sub-arc area andsaid second sub-arc area configured to be in flow communication withsaid arc plate area; a support coupled to said first wall and said sidewalls; at least one arc plate coupled to said support, said arc platehaving a body extending between said side walls and over said dividerwall, said at least one arc plate comprising a notch configured toreceive at least a portion of said divider wall; and a circuit breakercoupled to said housing and having a first sub-pole coupled within saidfirst sub-arc area and a second sub-pole coupled within said secondsub-arc area.
 12. The power distribution system of claim 11, whereinsaid at least one arc plate includes a first end coupled to said supportadjacent one said side wall and a second end coupled to said supportadjacent another said side wall.
 13. The power distribution system ofclaim 11, wherein said at least one arc plate is positioned over saidfirst sub-arc area and said second sub-arc area.
 14. The powerdistribution system of claim 11, wherein said at least one arc plateincludes a first recess positioned over said first sub-arc area and asecond recess positioned over said second sub-arc area.
 15. The powerdistribution system of claim 14, wherein said notch is between saidfirst recess and said second recess.
 16. The arc chute assembly of claim11, wherein said divider wall has a height less than a height of atleast one of said side walls.
 17. The power distribution system of claim11, wherein said arc plate area is configured to distribute gas pressureformed in said first sub-arc area and said second sub-arc area.
 18. Amethod of manufacturing an arc chute assembly, the method comprising:forming a housing having a first wall, a second wall, and a pair of sidewalls coupled to the first wall, said walls configured to form an arcarea; positioning a divider wall between the side walls, the dividerwall configured to form a first sub-arc area, a second sub-arc area, andan arc plate area within the housing; forming a notch in at least onearc plate; and coupling the at least one arc plate to the housing suchthat the notch receives at least a portion of the divider wall, the atleast one arc plate having a body extending between the side walls andover the divider wall.
 19. The method of claim 18, wherein forming thedivider wall comprises forming the first sub-arc area and the secondsub-arc area in flow communication with the arc plate area.
 20. Themethod of claim 18, wherein coupling the at least one arc plate to thehousing comprises positioning a first recess of the at least one arcplate over the first sub-arc area and positioning a second recess of theat least one arc plate over the second sub-arc area.